<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
  <style>
    #d1{
      width: 200px;
      height: 200px;
      border-bottom: 10px solid lightskyblue;
        /*设置圆角,值越大越圆*/
        border-radius: 20px;
    }
    #d2{
        width: 100px;
        height: 100px;
        border: 1px solid red;
        /*给元素添加内边距会影响元素的宽高*/
        padding-left: 50px;
        padding-top: 100px;
    }
  </style>
</head>
<body>
<div id="d1">边框测试</div>
<div id="d2">内边距</div>
</body>
</html>